This issue is the Default VOIP volume levels, specifically s_volume_voipin_db and s_volume_voipout_db being set to -6...
This causes any player who hasn't fixed this for their client by correcting the configuration using Direct Console Commands or an Autoexec.cfg file with the commands embedded... to have completely inadequate volume levels for their VOIP.
This is unacceptable as even with the utmost work by the player setting up a fireteam and conveying how to use fireteam chat to the other players, the first and last response of most players is "I can barely hear you"
Please keep this thread visible to SD... This issue needs to be fixed immediately